On 1/14/2018 3:03 PM, jbeattie wrote:
On Sunday, January 14, 2018 at 10:22:48 AM UTC-8, Tim McNamara wrote:
On Sat, 13 Jan 2018 15:16:09 -0800 (PST), dstamat
wrote:
Dear All,

I would like to buy a short (i.e. less that 150mm)
hollowtech-compatible 104BCD 4-arm single-ring (~42mm chainline)
crank. Do you have any suggestions?

I don't know about the Hollowtech compatibility- you may not be able to
find that specifically- but there is a trend amongst the recumbent folks
to 150 mm cranks. A local-to-me guy, Mark Stonich, has a business of
shortening cranks and might be a resource to talk to. He's done a *lot*
of this. His site mentions cranks from 90-160 mm.

http://bikesmithdesign.com

Mark is a very smart guy and is practically his own fringe element in
cycling. Who else would design manufacture a cotter pin press and a BB
cup removal tool for old British three speeds?

I don't know of anyone more knowledgeable about short cranks. I've got
a few reclining friends who use his services.

I used a version of these crank shorteners on the tandem when my son was small. https://www.amazon.com/Ride2-Crank-S.../dp/B002N2KJ7W
There are all sorts of crank shorteners on the market.

In the pre-internet days when I needed some for my kid, I didn't know
where to find them. My budget was slim, and I had access to a good
machine shop, so I made my own.

I've still got them, waiting for the grandkids' use.

--
- Frank Krygowski